R Ffrench-O'Carroll, K Fitzpatrick1, W R Jonker1, M Choo2, O Tujjar1. 1. Department of Anaesthesia, Intensive Care and Pain Medicine, Saolta University Healthcare Group, Sligo University Hospital, Sligo, Ireland. 2. Ear Nose and Throat Surgery, Saolta University Healthcare Group, Sligo University Hospital, Sligo, Ireland.